Retrievable well packer

ABSTRACT

A well packer, which is provided with upper and lower slips and expanders for permanent anchoring in a casing, is also provided with retrieval means by which the slips may be disengaged without damage to either the packer or the casing. A special slotted retrieval sleeve or the like is provided for supporting the upper ends of a plurality of spacing bars wedged longitudinally between the elastic packing bodies and the upper expander. After the packer has been anchored, the sleeve may be lifted to remove the support provided to the upper ends of the bars, whereupon these ends of the bars will be driven loosely under the upper expander. The upper expander will thereafter not support the upper slip, and the packing bodies can relax to enable retrieval of the packer from the well.

United States Patent [72] Inventor James W. Kisling, 111

' Houston, Tex. [21 Appl. No. 889,658 [22] Filed Dec. 31,1969 [4S]Patented Aug. 31, 1971 [73] Assignee Schlumberger Technology CorporationNew York, N.Y.

[54] RETRIEVABLE WELL PACKER 12 Claims, 8 Drawing Figs. 52 us. or116/134, 166/123 511* 1m.c| ..E2lb 23/06, E2 1 b 33/129 [50] FieldofSearch 166/134, 135,123,125,120,124

[56] References Cited UNITED STATES PATENTS 3,013,610 12/1961 Conradm.166/134 3,215,207 11/1965 Sizer 166/134 X 3,374,837 3/1968 Page et al.166/134 X 3,398,795 8/1968 Eliston.... 3,416,609 12/1968 Kilgore PrimaryExaminerDavid H. Brown AI10rneys-Ernest Archambeau, .lr., Wm. Beard,Stewart F.

Moore, David L. Mosely, Edward M. Roney and William R. Sherman ABSTRACT:A well packer, which is provided with upper and lower slips andexpanders for permanent anchoring in a casing, is also provided withretrieval means by which the slips may be disengaged without damage toeither the packer or the casing. A special slotted retrieval sleeve orthe like is provided for supporting the upper ends of a plurality ofspacing bars wedged longitudinally between the elastic packing bodiesand the upper expander. After the packer has been anchored, the sleevemay be lifted to remove the support provided to the upper ends of thebars, whereupon these ends of the bars will be driven loosely under theupper expander. The upper expander will thereafter not support the upperslip, and the packing bodies can relax to enable retrieval of the packerfrom the well.

PATENTED AUG31 1971 3,602,305

sum 1 or 3 James W. Kislinq 111 IN VE N TOR ATTORNEYS PATENTEU mm Ian II 3,602,305

SHEET 2 UF 3 Q' no END 2: & i/

James W. Kislinq III F /G.3 INVENTOR ATTORNEYS PATENTEDAUBBHBTI3.602.305

SHEET 3 UF 3 James W. Kislinq III IN VE N TOR AT TORNE YS RETRIEVABLEWELL PACKER BACKGROUND OF INVENTION This invention relates to wellpackers and the like, and more particularly relates to permanentlyanchored packers which are adapted to be retrieved without damage toeither the well or the packer.

There are many instances such as production operations wherein it isdesirable to define and segregate one portion of a borehole fromanother. In those instances wherein the borehole is lined with a steelcasing or the like, this is achieved by setting a packer assembly in thecasing at such depth as may be desired.

In some instances, it may be desired that the well be packed off" onlytemporarily, wherein in many other instances it is intended that thepacker be permanently set in the well. So-called temporary packers areusually designed to be wedged in the casing in such manner as to resistmovement in only one direction. This is because retrieval of a temporarypacker is usually achieved by shifting in the opposite direction todisengage it from the interior of the casing or tubing. n the otherhand, permanent" packers are wedged in the casing in a manner opposingmovement in either direction. Hence, permanently anchored packers ofconventional design cannot be dislodged without damage either to thecasing or to the packer, inasmuch as movement of the packer tends to jamthe slips more firmly into engagement with the casing.

It is common occurrence for 'it to become desirable to remove a packerthat has been permanently installed. Since this usually requires adrilling operation and consequent destruction of the packer, this may bequite costly. Moreover it has become common to construct permanentpackers or drillable materials so that they can be easily shattered bythe drill bit. Although this provides a substantial saving insofar asdrilling time is concerned, it has the disadvantage that a' frangiblepacker may be an inherently weaker packer. Furthermore, the fragmentsand other debris from the shattered packer tend to clutter the bottom ofthe borehole, and may interfere with subsequent operations. In addition,a permanent packer is an expensive piece of equipment as such.

There have been many attempts to provide a packer which is adapted to beanchored immovablyin the borehole, but which. is also adapted to beretrieved whenever desired without damage to either the packer or theinterior of the borehole or casing. However, none of these retrieval permanent packers have met with complete acceptance by the oil and gasindustry.

In many cases, the packers have been both anchorable and retrievable,but either special setting techniques or equipment have been required toinstall the packer, or else special retrieval techniques and equipmenthave been necessary. In these cases, it has often cost more to retrievesuch a packer than it would have cost to drill through and destroy it.Other packers such as that depicted in U.S. Pat. No. 3,398,795, havebeen capable of being installed and retrieved by special setting andremoval equipment, however, such equipment and the packer itself arequite complicated and expensive.

These and other disadvantages of the prior art are completely overcomewith the present invention, however, and novel packer means is providedherein which may be anchored irnmovably in a well casing or the like byconventional setting techniques, but which may also be adapted to beselectively retrieved by conventional retrieval techniques and equipmentwithout damage to either the packer assembly or the casing.

SUMMARY OF INVENTION In a preferred embodiment of the present invention,a well packer assembly is provided with one or more elastic annularpacking bodies, and with upper and lower slip and slip-expam ders foranchoring the packing bodies into locked fluidtight engagement with theinside surface of a casing in a generally conventional manner. However,the packer assembly is further provided with an assembly of spacing barsand a sleeve member of special configuration which may be engaged andraised to disengage the slips and expanders without significant damageto any portion of the packer assembly except for expendable shear pinsand the like.

More particularly, the sleeve is provided with spaced-apart upper andlower longitudinal slots and is mounted at the upper end of the mandrelof the packer assembly. The upper slips are slidably mounted on theupper end of the special release sleeve, and further provided withsplines or inwardly directed shoulder portions extending in the upperslots of the sleeve, whereby the sleeve may be moved upwardly betweenthe upper slips and the mandrel while the slips are wedged between thecasing and the upper expander. The upper expander is similarly providedwith inwardly directed shoulder portions extending between the lowerslots in the release sleeve, and a plurality of spacing bars are mountedlongitudinally between the upper expander and the elastic bodies withtheir upper ends jammed against abutment surfaces on the lower expanderand the release sleeve. The lower ends of the spacing bars arepreferably wedged adjacent the surface of the mandrel, and thus the barswill be tilted upwardly and outwardly of the mandrel when the packerassembly is fully installed in the casing.

The upper end of the release sleeve is also preferably provided withinside ratchet threads or other suitable means for receiving andengaging the lower end of a grapple-type retrieving member. Accordingly,after the packing assembly has been permanently installed in a casing,it may be easily dislodged and removed by merely stabbing the retrievingmember into the upper end of the sleeve, and by thereafter lifting thesleeve a limited distance sufficient to pull the lower end or edge ofthe sleeve from between the mandrel and the upperends of the spacingbars.

The upper ends of the spacing bars are preferably canted downwardly andoutwardly of the mandrel, the same as the edges of the upper expanderagainst which the bars are jammed. As long as the lower edge of thesleeve is wedged between the mandrel and the upper ends of the spacingbars, however, the bars will remain wedged longitudinally between theelastic packing bodies and the upper expander.

On the other hand, when the sleeve is lifted free of the upper ends ofthe spacing bars, this removes their support, and the compressed packingbodies will relax sufficiently to drive the upper ends of the barsinwardly between the mandrel and the upper expander. This, in turn,completely releases the resistance to downward movement of the upperexpander which upwardly wedges the upper slips against the insidesurface of the casing. Accordingly, the sleeve may then be lifted afurther distance sufficient to catch and lift the upper slips completelyfree of the upper expander without damage to either the expanders or thecasing.

The foregoing action will, of course, permit complete upward relaxationof the elastic packing bodies and this, in turn, removes the downwardpressure which jams the lower slips between the casing and the lowerexpander. Accordingly, the sleeve and upper slips may be interconnectedsuch that sufficient upward travel of the sleeve will eventually engageand lift the packing assembly including the lower slips and expander outof the casing.

These and other features and advantages of the present invention will beapparent from the following detailed description wherein reference ismade to the figures of the accompanying drawings.

IN THE DRAWINGS:

FIG. 1 is a pictorial representation, partly in cross section, of apacking assembly embodying the concept of the present invention anddisposed for permanent installation in a well casing or the like.

FIG. 2 is a similar representation of the apparatus depicted in FIG. 1,illustrating the packing assembly after such installation.

FIG. 3 is also a similar representation of the apparatus depicted inFIGS. 1 and 2, but illustrating the details and relative position of itsvarious components after the packing assembly has been released from thecasing.

FIG. 4 is a pictorial representation of a preferred embodiment of therelease sleeve hereinbefore described, and which is depicted in crosssection in FIGS. l3.

FIG. 5 is a cross-sectional representation of a portion of the apparatusdepicted in FIG. 1.

FIG. 6 is a cross-sectional representation of another portion of theapparatus depicted in FIG. 1.

FIG. 7 is a cross-sectional representation of a further differentportion of the apparatus depicted in FIG. 1.

FIG. 8 is a cross-sectional representation of another different portionof the apparatus depicted in FIG. 1.

DETAILED DESCRIPTION Referring now to FIG. 1, there may be seen apictorial representation, partly in cross section, of a packing assemblydisposed longitudinally in a well casing 2 or the like for permanentanchorage therein. In particular, the packing assembly may include ahollow tubular mandrel 11 having a special retrieval sleeve 9 slidablydisposed about its upper end, and further having one or more elasticannular packing bodies circumferentially mounted about its exteriorbelow the sleeve 9. An expandable annular upper slip 13 may be slidablypositioned about the upper end of the mandrel 11 below a plurality ofspaced-apart shoulder extensions 12, and an upper expander I4 ispreferably disposed about the mandrel l1 and sleeve 9 below the upperslip 13. A lower slip expander 23 may be mounted about the mandrel 11below the packing bodies 20 and above an expandable lower slip 24. Moreparticularly, the lower edge of the lower expander 23 may be wedgedbetween the mandrel l1 and the lower slip 24, and may be secured theretoby a shear pin 25 or other suitable means. The lower end of the mandrell 1 may be provided with a conventional end collar 30, and a springsupport collar 29 may be mounted abovethe end collar and secured to themandrel l l by any suitable means such as a pin 28. 1 As may be furtherseen, the spring support collar 29 is provided with an interior annularcavity or recess for supporting a helical spring 26 having its upper endurged against a suitable spacer ring 32, or the like, positioned betweenthe upper end of the spring support collar 29 and the lower abutting endof the lower slip 24. A stop ring 27 may be provided between the supportcollar 29 and the adjacent surface of the mandrel 11, which togetherwith a stop ring 21 between the expander 23 and the mandrel preventpremature setting of the lower slip '24 and the packing 20 duringrunning. An annular drive ring 22 may be located in an elongated recessabout the mandrel ll to limit upward and downward travel of the lowerexpander 23.

Referring again to FIG. 1, the apparatus preferably includes an annularabutment member 19 of conventional design mounted about the mandrel 11immediately above the upper surface of the uppermost packing body 20. Aplurality of rigid spacing bars 16 may be provided in groups at suitablelocations about the exterior of the mandrel l1, and aligned between theupper expander 14 and the abutment member 19. More particularly, thelower ends of the spacing bars 19 may be seen to be seated adjacent themandrel 11 in an annular internal recess in the abutment member 19 andmay also be secured to the abutment member 19 by suitable pins 18 or thelike. The upper ends of the spacing bars, however, are preferably wedgedbetween the lower tapered edges of the downwardly extending fingers ofthe retrieval sleeve 9 (see FIG. 4) and an internal annular recess inthe upper expander 14. A suitable shear pin 17 or the like may beprovided for linking the upper expander 1 to the sleeve 9.

The packing assembly as depicted in FIG. 1 may be anchored by aconventional setting tool 3 comprising a compressional member 5 (shownin phantom lines) arranged to be driven downwardly against the uppersurface of the upper slip l3, and a tension member 4 for drawing themandrel 11 upwardly in the casing 2. In particular, the tension member 4may be composed of an elongated member or bar disposed within themandrel 11 and having a locking rim 7 at its lower end. In addition, acollet ring having a plurality of collet fingers 8 may be slidablydisposed about the lower end of the tension member 4 with the tips ofthe fingers 8 locked to the locking rim 7 by one or more shear pins 6and extending below the lower end of the mandrel ll. Accordingly,'thepacking as sembly depicted in FIG. 1 may be anchored in the casing 2 bysimultaneously moving the compression member 5 downwardly through thecasing 2 and drawing the tension member 4 upwardly therethrough. Thiswill first cause the upper slip 13 to be shifted by the expander 14 intogripping engagement with the casing, whereupon the mandrel 11 will beginto travel upwardly. Upward movement of the mandrel 1 l is transmitted bythe drive ring 22 to the lower expander 23 which compresses and expandsthe packing 20 into sealing contact with the casing 2. During setting ofthe packing 20, the shear pins 25 will fail and enable the coil spring26 to shift the slips 24 outwardly along the expander 23 and against theeasing. The spring 26 continues to press the slips 24 into wedgingengagement between the upper expander 14 and the casing 2.

When the upper and lower slips l3 and 24 and the packing 20 have beenset forcefully against the casing 2, further upward movement of thetension member 4 will shear the pins 6, and will thereafter pull thelocking rim 7 upwardly to free the tips of the collet fingers 8. Thecollet fingers 8 may then resile inwardly so that "they may be drawnupwardly through the mandrel 11. Accordingly, the setting tool 3 maythen be removed from the casing 2.

Referring now toFIGS. 4-8, there may be seen a pictorial representationof the special retrieval sleeve 9, and detailed cross-sectionalrepresentation of the related portions of the assembly at variouslocations. More particularly, the sleeve 9 may be seen in FIG. 4 to havea plurality of equally spacedapart and aligned upper and lower extendingfingers 37 and 35 respectively, which form upper and lower longitudinalslots 36 and 38. The upper ends of the fingers 37 may be seen to beprovided with internal ratchet threads 10 to engage the end of asuitable retrieval tool, and the lower fingers 35 may be seen to beprovided with tapered tips to slidably support the upper ends of thespacing barsl6 as hereinbefore described. The central annular orringlike portions 34 of the sleeve 9 separates the upper and lower slots36 and 38.

Referring again to FIG. 8, the upper beveled ends of the spacing bars 16are wedged between the tapered surfaces of the lower fingers 35 andagainst the correspondingly beveled inner surface 39 of the upperexpander 14. Referring now to FIG. 5, there may be seen a representationof the spacedapart, shoulderlike extensions 12 which are located to ridebetween the upper fingers 37 of the sleeve 9, and further located to beengaged by the upper slip 13 when the slip 13 is carried upward alongthe mandrel 11 by the sleeve 9, as will hereinafter be explained.

Referring now to FIG. 2, there may be seen a pictorial representation,partly in cross section, of the packing assembly depicted in FIG. 1after such assembly has been anchored in the casing 2. Moreparticularly, the upper slip 13 has been driven downwardly along theinterior surface of the expander 14 and into gripping engagement withthe casing 2. Similarly, the lower expander 23 may be seen to have beendriven upwardly against the packing bodies 20 to compress and expandthem outwardly against the interior surface of the casing 2. In thisrespect, the lower slip 24 will also be seen to have been wedged betweenthe lower expander 23 and the casing 2, after severing of the connectingshear pin 25. After the upper and lower slips 13 and 24 have beenanchored, and after the setting tool 3 has been removed from the casing2,

the well packer will remain immovable in the casing until it is desiredto remove it.

Referring now to FIG. 3, there may be seen a similar representation ofthe apparatus depicted in FIGS. 1 and 2, wherein a retrieval tool 40 hasbeen stabbed into the upper end of the special retrieval sleeve 9 forthe purpose of engaging the threads 10. Accordingly, when the retrievaltool 40 is drawn upwardly through the casing 2 a sufiicient distance,the taper lower ends of the fingers 35 are first disconnected from theshear pin 17, and are thereafter drawn from under the upper ends of theoutwardly directed spacing bars 16. After these tapered ends of thelower fingers 35 clear the upper ends of the spacing bars 16,decompression of the packing bodies will drive the upper ends of thespacing bars 16 under the upper expander 14, and release the compressionloading in the system.

The packing bodies 20 will completely relax to release the fluidtightengagement with the interior surface of the casing 2, and the upperexpander 14 no longer supports the upper slip 13 with respect to thecasing.

The retrieval tool 40 may now be further lifted through the casing 2until the central annular portion 34 of the sleeve 9 engages theinterior abutting portions 41 of the upper slip l3. Upward travel of theretrieval tool 40 will then cause the sleeve 9 to carry the upper slipl3 completely free of the casing 2, and from the upper part of the upperexpander 14.

The packing bodies 20 may now be assumed to be fully relaxed anddecompressed. However, the spring 26 may still be compressedsufficiently to drive the lower slip 24 upwardly into partial engagementbetween the casing 2 and the lower expander 23. Nevertheless, when thesleeve 9 has been raised sufficiently to drive the upper end of theupper slips 13 into abutting engagement with the lower side of theshoulders 12, this will cause the mandrel 11 to be lifted through thecasing 2 and the stop ring 22 to lift the lower expander 23 out fromunderneath the lower slips 24. Then the entire assembly may be liftedfree of the casing 2.

It will be apparent from the foregoing that many other variations andmodifications may bemade in the structures and methods described hereinwithout substantially departing from the essential concept of thepresent invention. Accordingly, it should be clearly understood that theforms of the invention described herein and depicted in the accompanyingdrawings, are exemplary only and are not intended as limitations in thescope of the present invention.

What is claimed is:

l. A well packer apparatus comprising:

an elongated body member;

packing means on said body member adapted to be compressed and expandedinto sealing contact with a well casmg;

upper slip and expander means for anchoring against upward movement ofsaid body member in said casing; lower slip and expander means foranchoring against downward movement of said body member in said casing;support means on said body member for maintaining said upper slip andexpander means in fixed, spaced relation to said packing means and formaintaining said packing means in sealing contact with said casing; andmeans for disabling said support means to enable the upper end portionof said packing means to move relatively toward said upper slip andexpander means and to relieve said compression and expansion in saidpacking means.

2. The packer apparatus described in claim 1, wherein said disablingmeans includes a sleeve means slidably mounted on said body member andupwardly movable relative to said packing means for disabling saidsupport means. I

3. The packer apparatus described in claim 2, wherein said support meansis radially disposed about said body member between said sleeve memberand said expander means for maintaining said compression and expansionin said packing means.

4. The packer apparatus described in claim 3, wherein said support meansis radially disposed about said body member between said upper expandermeans and said packing means.

5. The packer apparatus described in claim 4, wherein said support meansis radially collapsible about said body member upon upward movement ofsaid sleeve member along said body member to release said upper expandermeans and said packing means.

6. A well packer apparatus comprising a mandrel,

an annular body member formed of a resilient material and concentricallymounted on said mandrel,

upper expander means slidably mounted on said mandrel above saidresilient body member,

lower expander means slidably mounted on said mandrel belowsaidresilient body member,

upper slip means downwardly movable along said mandrel for wedgingengagement between said upper expander means and the inside surface of awell casing or the like,

lower slip means upwardly movable along said mandrel for wedgingengagement between said lower expander and the inside surface of a wellcasing or the like,

a sleeve means slidably movable on said mandrel independently of saidexpander means and said slip means and having one end extending at leastpartially between said upper expander and said mandrel, and

support means at least partially disposed between said upper expandermeans and the upper end of said body member for maintaining a spacedrelationship therebetween.

7. The packer apparatus described in claim 6, wherein said support meanscomprises a plurality of rigid members disposed about said mandrel andeach having one end adjacent said resilient body member and the otherend wedged between said upper expander means and said end of said sleevemember.

8. The packer apparatus described in claim 7, wherein said rigid membersare elongated bar members longitudinally aligned with said mandrel.

9. The packer apparatus described in claim 8, wherein the ends of saidbar members adjacent said upper expander means are adapted to be drivenbetween said upper expander means and said mandrel by relaxation of saidresilient body member upon withdrawal of said sleeve member from betweensaid mandrel ans said upper expander means.

10. The packer apparatus described in claim 9, wherein said sleevemember is provided with a plurality of upper longitudinal slotsextending partially along said sleeve member for accommodating saidupper slip means, and

wherein said sleeve member is adapted to engage and draw said upper slipmeans out of wedging engagement between said upper expander means andsaid well casing after said end of said sleeve member is removed frombetween said ends of said bar members and said mandrel. 11. The packerapparatus described in claim 10, wherein said sleeve member is furtherprovided with a plurality of lower longitudinal slots extendingpartially along said sleeve member for accommodating said upper expandermeans.

12. The packer apparatus described in claim 11, wherein said upper slipmeans is adapted to be slidably movable along said mandrel between saidlower slots of said sleeve means.

1. A well packer apparatus comprising: an elongated body member; packingmeans on said body member adapted to be compressed and expanded intosealing contact with a well casing; upper slip and expander means foranchoring against upward movement of said body member in said casing;lower slip and expander means for anchoring against downward movement ofsaid body member in said casing; support means on said body member formaintaining said upper slip and expander means in fixed, spaced relationto said packing means and for maintaining said packing means in sealingcontact with said casing; and means for disabling said support means toenable the upper end portion of said packing means to move relativelytoward said upper slip and expander means and to relieve saidcompression and expansion in said packing means.
 2. The packer apparatusdescribed in claim 1, wherein said disabling means includes a sleevemeans slidably mounted on said body member and upwardly movable relativeto said packing means for disabling said support means.
 3. The packerapparatus described in claim 2, wherein said support means is radiallydisposed about said body member between said sleeve member and saidexpander means for maintaining said compression and expansion in saidpacking means.
 4. The packer apparatus described in claim 3, whereinsaid support means is radially disposed about said body member betweensaid upper expander means and said packing means.
 5. The packerapparatus described in claim 4, wherein said support means is radiallycollapsible about said body member upon upward movement of said sleevemember along said body member to release said upper expander means andsaid packing means.
 6. A well packer apparatus comprising a mandrel, anannular body member formed of a resilient material and concentricallymounted on said mandrel, upper expander means slidably mounted on saidmandrel above said resilient body member, lower expander means slidablymounted on said mandrel below said resilient body member, upper slipmeans downwardly movable along said mandrel for wedging engagementbetween said upper expander means and the inside surface of a wellcasing or the like, lower slip means upwardly movable along said mandrelfor wedging engagement between said lower expander and the insidesurface of a well casing or the like, a sleeve means slidably movable onsaid mandrel independently of said expander means and said slip meansand having one end extending at least partially between said upperexpander and said mandrel, and support means at least partially disposedbetween said upper expander means and the upper end of said body memberfor maintaining a spaced relationship therebetween.
 7. The packerapparatus described in claim 6, wherein said support means comprises aplurality of rigid members disposed about said mandrel and each havingone end adjacent said resilient body member and the other end wedgedbetween said upper expander means and said end of said sleeve member. 8.The packer apparatus described in claim 7, wherein said rigid membersare elongated bar members longitudinally aligned with said mandrel. 9.The packer apparatus described in claim 8, wherein the ends of said barmembers adjacent said upper expander means are adapted to be drivenbetween said upper expander means and said mandrel by relaxation of saidresilient body member upon withdrawal of said sleeve member from betweensaid mandrel ans said upper expander means.
 10. The packer apparatusdescribed in claim 9, wherein said sleeve member is provided with aplurality of upper longitudinal slots extending partially along saidsleeve member for accommodating said upper slip means, and wherein saidsleeve member is adapted to engage and draw said upper slip means out ofwedging engagement between said upper expander means and said wellcasing after said end of said sleeve member is removed from between saidends of said bar members and said mandrel.
 11. The packer apparatusdescribed in claim 10, wherein said sleeve member is further providedwith a plurality of lower longitudinal slots extending partially alongsaid sleeve member for accommodating said upper expander means.
 12. Thepacker apparatus described in claim 11, wherein said upper slip means isadapted to be slidably movable along said mandrel between said lowerslots of said sleeve means.